Monthly Archives: April 2008

Whether or not the oceans are net sources or sinks of CO2 is very important, since right now, atmospheric CO2 increases at only about one half the rate of human-induced CO2 emissions, because quite a bit is taken up by the oceans. The study back in 2007 by Le Quere et al on the decline of the Southern Ocean as a sink still looks like it is holding.

The planetary albedo (the percentage of the incoming solar radiation that is reflected back to space) plays a large role in the Earth’s radiative balance. The planet currently reflects about 30% of the incoming radiation back to space (clouds, particles in the atmosphere, ice sheets). If the albedo of the planet were 0 (all of it were absorbed) the planet would be over 20 degrees C hotter.

The March 2008 temperature data is available now. While some sources like Anthony Watts blog made a big deal out of anomalous January 2008 cooling (largely due to La Nina), and a DailyTech article went as far as to say that January 2008 cooling “cancelled out” a century of global warming. March 2008 recovered, but also jumped much higher than expected.

Aside from the total solar irradiance changes, changes in cosmic rays might be the next skeptic alternative to increases in greenhouse gases and other anthropogenic activities as the cause of modern global warming. It is an idea being investiaged a lot, though some like Henrik Svensmark and Nir Shaviv are very confident that they have overturned the CO2 paradigm and found a link between cosmic rays and low level cloud cover.